STRINGERLESS STRENGTH

Swayer peruser's - I have just finished shaping an EPS blank 5'10 * 21* 21/2 board with flat(ish) rocker. I have cut in double flyers and used a swallow tail, I have left alot of meat in this board with 50 / 50 rails around the nose and front of board before hardening up through the mid and tail. The board feels great under the arm - of note the board has alot of flex probaly due to the omission of a stringer. Given it is extremely light my idea was to  lay 2 layers of 6 oz with epoxy on top and bottom with a deck patch - pretty heavy glass work i know but EPS weight allows for it with out over doing it.

In terms of 'stiffening' the I have thought of possible laying some balsa or ply on the deck - Now the board is shaped i would rather move away from introducing a stringer.

My older brother is an enginer and he seems to think by drilling some small holes through the deck and filling with light weight resin mix would work well this would allow both the deck glassing and bottom glassing to be joined. Having scathed the net and lock's this idea although a little odd seems to be a good idea.

I am purpose building the board for a twin fin comp in a few weeks.

Any thouhts?

Cheers. 

 

 

The best way to stiffen a board may be, to glass the last third or quarter of the board's rails, (the tail), with graphite tape, (under extra glass). An advantage is the board's flex can be adjusted by grinding the graphite lap narrorer.

Sickdog

 

I have shaped and glassed 6 boards under 7’0" that were stringerless.

I used poly.

Double 6 deck, single 6 bottom.

I have yet to see one break.

I have cut slots into the blank from the nose and tail and inserted Balsa in 36 inch lengths.

Just in case.

 

Hey bee - have you thought about using rail-parallel channels carved into the foam un the deck?  1/2-3/4" deep, 2" wide, 2-3" oc from rail edges.  Worked for me on a couple stringerless xps builds that seemed ridiculously flexy until I glassed the channels.  6+6 deck and 6 bottom . . .

camplus - I have given thought to that - i guess it is similar to the idea my bro put forward of drilling holes 'piers' into the board so in effect joining the deck and botton together.

2 6oz on the deck enough? It seems pretty soft on the deck?

 

 

insert thin bamboo rods into the deck , a few inches in on the rails and epoxy them in with fibre strand......more twang than Duane Eddy !!!!

I think i have come up witht the solution. I will opt for q-cell epoxy mix set into drilled holes, following the line of where the stringer and parabolic stringers would be. maybee 10inches apart.

Now the million dollar questions...

To paint on the EPS foam or paint before hot coat?

How long do I let the board cure before riding? I want to ride the board in 11 days time - by the time the board is finsihed there will be about 4 days grace before it tastes the salt....

pics will follow.

Hi Bee, I read your thread and it sounds like you’ve made up your mind about those holes. I just wanted to tell you that I did that operation on my first board, only not in a straight line, but ALL OVER the entire gargantuan banana that I had crudely surformed out of pink xps foam. It was a lot of work, and added a lot of weight. I wasn’t doing them for added stiffness, though…I was hoping to counteract delamination by making a truss system. Hoping that the resin would evenly coat the inside of each hole, I resorted to filling them all solid, in the end. After I glassed it it looked like a bandaid. So I painted it and glossed it. I never weighed it, maybe a 20 lb board. Epoxy and glass alone would be strong enough without a stringer- I dunno if you wanna stiffen it cuz you like the ride better, or are you worried about yer board breaking? I just can’t see how holes 10" apart will do anything for stiffness in regards to either flex or durability. Impact resistance in the immediate area of the resin column, maybe. There’s lots of wood and bamboo threads on here, glassing schedule refernces, great pics for ideas…but if you’re bent on filling holes in a line, I’d suggest closer together than 10" or none at all

I’m riding a stringerless 5-8 stubbie. I used 2 layers of 4oz and wrapped both layers around the rails. I cut the layer closest to the foam longer than the top layer, and did this on both sides. The board feels pretty strong, and I’ve been out in overhead+ waves and have had late (in the lip) drops. 

Just make sure you wrap the rails with both layers of glass, and make the wrap generous. I don’t think you’ll need to add more than 2 layers top and bottom. I do a slight bevel on the bottom about an inch in from the edge to help from sanding off the wrap.

swayers - holes are out.

Just going with a nice glass job double 6 top single bottom - and see how it performs - no time to dilly daddle I have a twin fin comp saturday week i have made this board for.

everybody thanks for the heads up.

time to live the dream

 

swayers - holes are out.

Just going with a nice glass job double 6 top single bottom - and see how it performs - no time to dilly daddle I have a twin fin comp saturday week i have made this board for.

everybody thanks for the heads up.

time to live the dream

 

any pics ???   I have done several stringerless and about to do quite a few MORE...I have used carbon fibres in the cloth before ( works with epoxy ) and a recent one has carbon-kevlar rail bands ( maybe some call it tape ? ) and glassing it with epoxy ( PU foam ), have also dragged a wax comb hard down where a stringer would be, just to give some grooves where resin can fill up, just a touch more strength, have also put a fabric inlay on the deck ( no strength but looks cool ) and done bigger laps than usual.... this'll be a tester and see how it holds up before planing on how I will do my stringerless in the future...have great memories of my first stringerless and hoping to re-create that same lively flexy feel.....

Will post some pics over the next few days - laminated the bottom today with a pathch and a six ounce...soft, but should harden once resin sets.

Bee,

I'm glad to see you opted out of drilling holes.  For what it's worth, if you haven't already read deadshaper's advice in a thread titled "Stringerless Longboard" in March '07, I'd suggest it.  Sharkcountry's advice follows the theory contained therein, and he too knows a thing or three about boardbuilding.  I'm halfway through glassing a stringerless 5'8" myself.  No extra holes.

My only concern is you don't mention what density foam you used.

Best wishes.

I am in the process of shaping a 5' 11" stringerless XPS fish, 21" wide and 3" thick.  I am planning on using 3x6oz on the top and bottom both with generous laps around rails.  From others I have spoken to this should give me a stiff enough board (I am 185lbs) since it will have 6 layers of 6oz on the rails.  Heres the rockered blank before I started shaping the rails, will add more as I go.

https://swaylocks7stage.s3.us-east-2.amazonaws.com/s3fs-public/fish1.JPG

I still have a RR epoxy 6’ x 22.5" x 2.75" thick S decked stubby from when I was 210-220 lbs. Hotwire cut by me from 2# EPS insulation billet.

I had it glassed by a pro and it is 3 x 6oz on top and 2x on bottom.   Stiff as shit, no dings or even pressures at all about 2 years later.  I would do it lighter nowadays, even if I still had that 37 extra lbs on me.

Slowly slowly this boy needs help.

 

I have noted after doing my first deck layer there is air in some points under join where the bottom lap and the top layer pass. only in a few places. (my first proper glass job).

 

Plan is to rectify -

1. i didnt bother doing the full lap - just went a 1/3 onto the existing lap.

2. let it dry.

3. go back and inject epoxy into the gaps.

4. hopefully have a fully sealed board.

5. go on and do my two other layers.

 

In honesty im not being critical of this board as im making it for fun but i wont to save it and get a few rides out of it.

my tip never glass after 12 hour night shifts.

the funny thing is it feels great under the arm and i cant wait to get it in the salt

As I work on this stringerless board I am finding I wish I had a stringer just as its such a good reference point that doesnt sand away and gives some strength to the blank as you sand, particualry in the nose.  I have been leaving the nose until last to form as I dont want to skew it or snap it off.  I will see how it works, but I think I will go with a stringer on the next one just as it makes it easier to work.  Heres the progress I made last night

https://swaylocks7stage.s3.us-east-2.amazonaws.com/s3fs-public/shaped.JPG

[img_assist|nid=1047754|title=stringerless1|desc=|link=none|align=left|width=75|height=100][img_assist|nid=1047755|title=simmons stringerless|desc=|link=none|align=left|width=100|height=75]

 

 

 

 

 

The blue longboard is 9’2", stringerless but has 3/32nds Balsa insterted 3’ in, offset, nose and tail.

Flexes from the nose and tail but no stress cracks or anything showing and I surfed it a few days ago in 6’ at 22 secs here in Oregon.

The yellow board is 6’10", double six bottom, double six deck, stringerless, ridden in surf up to 8’ and never a problem.

 

surfinghigh, I could not see the stringer insert due to the small photo size, but do I understand you to say you insert a 3' long section in the tail and nose as a centerline so its easier to work or when you say off-set, do you mean two off-center on the nose and tail?

Wow, you were out in the last weeks cold!!?  I wanted to go to Westport as the waves looked nice but the temps in the teens here in WA put me off.